CN117185137A

CN117185137A - Tower crane track discretization method, device, computing equipment and storage medium

Info

Publication number: CN117185137A
Application number: CN202311141173.0A
Authority: CN
Inventors: 齐斌
Original assignee: Kyland Technology Co Ltd
Current assignee: Kyland Technology Co Ltd
Priority date: 2023-09-05
Filing date: 2023-09-05
Publication date: 2023-12-08

Abstract

The embodiment of the application relates to the technical field of intelligent construction, and relates to a method, a device, equipment and a medium for discretizing a tower crane track. The scheme of the discretization method for the tower crane track is as follows: determining gear separation speed between adjacent operation gears according to gear speed of each operation gear of the tower crane; acquiring the planning speed of each track point on the original planning track; obtaining a gear speed adapted to the planning speed according to the gear separation speed; and replacing the planning speed with the adapted gear speed for each track point on the original planning track to obtain a discretized planning track. The embodiment of the application provides a discretization method for a tower crane track adapted to gear control, so that the tower crane track can meet the kinematic characteristic and discretize the speed output into the gear speed, the control precision of the tower crane is improved through track discretization, and the safety risk is effectively reduced.

Description

Tower crane track discretization method, device, computing equipment and storage medium

Technical Field

The application relates to the technical field of intelligent construction, in particular to a method, a device, computing equipment and a storage medium for discretizing a tower crane track.

Background

The tower crane is widely applied to the fields of building and infrastructure construction and the like. The control of traditional tower crane needs a driver and a ground commander to operate together, has intensity of labour big, the high pain point of security risk. In recent years, the implementation mode of the unmanned tower crane is always explored in the construction field, but most of the implementation modes only save the driver at high places and change the implementation mode into the cloud control on the ground. For example, a model is built in a laboratory environment by adopting fuzzy control, synovial membrane control, genetic algorithm, neural network and the like to simulate so as to accurately control the unmanned tower crane. However, the control outputs of these methods are directed to continuous control amounts and output amounts. In practical application, many unmanned towers are based on the traditional gear control tower crane motion, namely, only the gear IO (input and output) can be sent. Therefore, the existing control output and control mode are not adapted, the control precision of the unmanned tower crane is limited, and the accurate control of the unmanned tower crane cannot be realized.

Disclosure of Invention

In view of the above problems in the prior art, the embodiment of the application provides a method, a device, a computing device and a storage medium for discretizing a tower crane track, and provides the method for discretizing the tower crane track by adapting to gear control, so that the tower crane track can meet kinematic characteristics and discretize speed output into gear speed, the control precision of the tower crane is improved through track discretization, and the safety risk is effectively reduced.

The first aspect of the present application provides a method for discretizing a tower crane track, comprising:

determining gear separation speed between adjacent operation gears according to gear speed of each operation gear of the tower crane;

acquiring the planning speed of each track point on the original planning track;

obtaining a gear speed adapted to the planning speed according to the gear separation speed;

and replacing the planning speed with the adapted gear speed for each track point on the original planning track to obtain a discretized planning track.

As a possible implementation manner of the first aspect, the method further includes:

measuring the gear speed of the highest gear in the running gears;

and calculating the gear speed of each running gear according to the gear speed of the highest gear and the Hertz value of the frequency converter corresponding to each running gear.

As a possible implementation manner of the first aspect, the determining, according to a gear speed of each operation gear of the tower crane, a gear separation speed between adjacent operation gears includes:

and taking the average value of the gear speeds of two adjacent running gears as the gear separation speed between the adjacent running gears.

As a possible implementation manner of the first aspect, the obtaining, according to the gear separation speed, a gear speed adapted to the planned speed includes:

for each of the operating gear, determining a section between two gear separation speeds adjacent to the gear speed as a speed section corresponding to the operating gear;

and aiming at each track point on the original planned track, if the value of the planned speed of the track point is within the speed interval, taking the gear speed of the running gear corresponding to the speed interval as the gear speed matched with the planned speed.

dividing the original planned trajectory into a plurality of segmented trajectories based on different speed directions;

for each track point on the segmented track, extracting the absolute value of the planning speed of the track point, and storing the speed direction information of the track point;

obtaining a gear speed adapted to the absolute value of the planning speed according to the gear separation speed;

for each track point on the segmented track, replacing the absolute value of the planning speed with the adapted gear speed to obtain a discretized segmented track;

Adding the information of the speed direction to the respective segmented trajectories; and synthesizing the segmented tracks to obtain a discretized planned track.

based on the planning speed corresponding to each track point on the original planning track, obtaining a first path through integral calculation;

obtaining a second path through integral calculation based on the gear speed adapted to each track point on the discretized planning track;

and correcting the end point of the second path according to the end point of the first path under the condition that the path difference between the first path and the second path is smaller than a preset threshold value.

and under the condition that the range difference is larger than or equal to a preset threshold value and the range difference diverges, sequentially performing downshift processing on the adapted gear speed of the designated track point according to a preset sequence.

and under the condition that the distance difference is larger than or equal to a preset threshold value and the distance difference is not divergent, adjusting the gear separation speed according to the distance difference.

The second aspect of the application provides a discretizing device for tower crane track, comprising:

a first processing unit for: determining gear separation speed between adjacent operation gears according to gear speed of each operation gear of the tower crane;

an acquisition unit configured to: acquiring the planning speed of each track point on the original planning track;

a second processing unit for: obtaining a gear speed adapted to the planning speed according to the gear separation speed;

a discrete processing unit for: and replacing the planning speed with the adapted gear speed for each track point on the original planning track to obtain a discretized planning track.

As a possible implementation manner of the second aspect, the apparatus further includes a third processing unit, where the third processing unit is configured to:

measuring the gear speed of the highest gear in the running gears;

As a possible implementation manner of the second aspect, the first processing unit is configured to:

As a possible implementation manner of the second aspect, the second processing unit is configured to:

As a possible implementation manner of the second aspect, the second processing unit is further configured to: dividing the original planned trajectory into a plurality of segmented trajectories based on different speed directions; for each track point on the segmented track, extracting the absolute value of the planning speed of the track point, and storing the speed direction information of the track point; obtaining a gear speed adapted to the absolute value of the planning speed according to the gear separation speed;

the discrete processing unit is further configured to: for each track point on the segmented track, replacing the absolute value of the planning speed with the adapted gear speed to obtain a discretized segmented track; adding the information of the speed direction to the respective segmented trajectories; and synthesizing the segmented tracks to obtain a discretized planned track.

As a possible implementation manner of the second aspect, the discrete processing unit is further configured to:

A third aspect of the application provides a computing device comprising:

A communication interface;

at least one processor coupled to the communication interface; and

at least one memory coupled to the processor and storing program instructions that, when executed by the at least one processor, cause the at least one processor to perform the method of any of the first aspects above.

A fourth aspect of the application provides a computer readable storage medium having stored thereon program instructions which when executed by a computer cause the computer to perform the method of any of the first aspects above.

These and other aspects of the application will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

Drawings

The various features of the application and the connections between the various features are further described below with reference to the figures. The figures are exemplary, some features are not shown in actual scale, and some features that are conventional in the art to which the application pertains and are not essential to the application may be omitted from some figures, or additional features that are not essential to the application may be shown, and the combination of features shown in the figures is not meant to limit the application. In addition, throughout the specification, the same reference numerals refer to the same. The specific drawings are as follows:

Fig. 1A is a schematic structural diagram of an application scenario according to embodiments of the present application;

FIG. 1B is a schematic diagram of a tower crane according to various embodiments of the present application;

FIG. 2 is a schematic diagram of an embodiment of a method for discretizing a trajectory of a tower crane according to an embodiment of the present application;

FIG. 3 is an exemplary graph of data calculation results of a gear speed and a gear separation speed according to an embodiment of a method for discretizing a trajectory of a tower crane according to the present application;

FIG. 4 is a schematic flow chart of a discrete algorithm of an embodiment of a method for discretizing a trajectory of a tower crane according to an embodiment of the present application;

FIG. 5 is a schematic diagram of an embodiment of a discretizing apparatus for tower crane trajectories according to an embodiment of the present application;

FIG. 6 is a schematic diagram of an embodiment of a discretizing apparatus for tower crane trajectories according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a computing device according to an embodiment of the present application.

Detailed Description

The terms first, second, third, etc. or module a, module B, module C and the like in the description and in the claims, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order, and it is to be understood that the specific order or sequence may be interchanged if permitted to implement embodiments of the application described herein in other than those illustrated or described.

In the following description, reference numerals indicating steps such as S110, S120, … …, etc. do not necessarily indicate that the steps are performed in this order, and the order of the steps may be interchanged or performed simultaneously as allowed.

The term "comprising" as used in the description and claims should not be interpreted as being limited to what is listed thereafter; it does not exclude other elements or steps. Thus, it should be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the expression "a device comprising means a and B" should not be limited to a device consisting of only components a and B.

Reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments as would be apparent to one of ordinary skill in the art from this disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. If there is a discrepancy, the meaning described in the present specification or the meaning obtained from the content described in the present specification is used. In addition, the terminology used herein is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application. For the purpose of accurately describing the technical content of the present application, and for the purpose of accurately understanding the present application, the following explanation or definition is given for terms used in the present specification before the explanation of the specific embodiments:

1) Variable-frequency Drive (VFD): the power control device is a power control device which controls an alternating current motor by changing the frequency of a working power supply of the motor by applying a frequency conversion technology and a microelectronic technology. The frequency converter mainly comprises a rectifying unit (alternating current to direct current), a filtering unit, an inverting unit (direct current to alternating current), a braking unit, a driving unit, a detecting unit micro-processing unit and the like. The frequency converter adjusts the voltage and frequency of the output power supply by switching on and off the internal IGBT (Insulated Gate Bipolar Transistor ), and provides the required power supply voltage according to the actual requirement of the motor, thereby achieving the purposes of energy saving and speed regulation. In addition, the frequency converter has many protection functions, such as overcurrent, overvoltage, overload protection and the like.

2) TCP (Transmission Control Protocol ): is a connection-oriented, reliable, byte stream based transport layer communication protocol. TCP is intended to accommodate a layered protocol hierarchy that supports multiple network applications. Reliable communication services are provided by means of TCP between pairs of processes in host computers connected to different but interconnected computer communication networks. TCP assumes that it can obtain simple, possibly unreliable datagram services from lower level protocols. In principle, TCP should be able to operate over a variety of communication systems from hardwired to packet-switched or circuit-switched networks.

The prior art method is described first, and then the technical scheme of the application is described in detail.

The prior art has the following defects: the existing control output and control mode are not adapted, and the control precision of the tower crane is limited.

Based on the technical problems existing in the prior art, the embodiment of the application provides a method, a device, a computing device and a storage medium for discretizing a tower crane track, and provides the method for discretizing the tower crane track for adapting to gear control, so that the tower crane track can meet the kinematic characteristic and discretize the speed output into the gear speed, the control precision of the tower crane is improved through track discretization, the safety risk is effectively reduced, and the technical problems that the control output and control mode are not adapted and the control precision of the tower crane is limited in the prior art are solved.

The application provides various method embodiments, various device embodiments, computing equipment embodiments and storage medium embodiments for discretizing a tower crane track. The following describes application scenarios of embodiments of the present application with reference to fig. 1A and 1B.

Fig. 1A shows a control system of the tower crane of the present application, comprising a video device, a controller, a frequency converter, a motor and an encoder.

The video equipment is used for acquiring a reference point in the operation process of the tower crane lifting hook in advance, wherein the reference point comprises a starting position, a target position and a position which can pass through the front of an obstacle to be avoided. The reference point coordinates acquired by the video equipment are the coordinates of a user coordinate system. The video equipment and the controller are communicated through a Modubus TCP protocol.

Wherein, the motor is used for driving the removal of tower crane lifting hook. The tower crane comprises several shafts, i.e. several adjustment directions. Each shaft is driven by a motor.

The frequency converter is used for receiving the controller output planning speed and controlling the rotating speed of the motor according to the planning speed. One axis direction is correspondingly controlled by using a frequency converter.

The encoder is used for acquiring the actual position of the tower crane lifting hook in the moving process so as to help the tower crane lifting hook to avoid obstacles according to a planned track and reach a target position. The encoder and the controller are communicated through a Modubus 485 protocol.

The controller is used for generating a planning track of the tower crane lifting hook according to the reference points, determining the planning speed of each track point, and driving the frequency converter of the tower crane to control the lifting hook to bypass the obstacle according to the planning track and accurately reach the target position.

Wherein, each method embodiment of the application operates in a controller, and each device embodiment is deployed in the controller.

Fig. 1B shows a tower crane for use with embodiments of the present application, the tower crane comprising three axes, lift (Lift), swivel (Turn) and Swing. Wherein lifting is also called lifting, rotation is also called turning, and arm spreading is also called luffing.

The video device in fig. 1A obtains the coordinates of the tower crane hook in the user coordinate system, and the coordinates can be converted into the coordinates in the cartesian coordinate system in fig. 1B through the conversion matrix.

The structure of fig. 1B is an example of a tower crane, and in a practical scenario, the tower crane may include other numbers of axles, such as axles that move laterally and/or longitudinally along the rails.

Taking three shafts of lifting, rotating and arm expanding as an example, in the running process of a tower crane lifting hook, the three shafts respectively drive an alternating current motor to execute motion through three frequency converters, and the current position of each shaft is acquired through an absolute value encoder. The vision device transmits the main path point position to the controller through ModbusTCP according to the monitored obstacle position. The controller sends the motion instruction to the three frequency converters through the Modbus485 bus, and meanwhile, the position information of the three encoders is acquired.

Fig. 2 is a schematic diagram of an embodiment of a method for discretizing a track of a tower crane according to an embodiment of the present application. As shown in fig. 2, the method specifically may include:

step S110, determining gear separation speed between adjacent operation gears according to gear speed of each operation gear of the tower crane;

step S120, obtaining the planning speed of each track point on the original planning track;

Step S130, obtaining a gear speed adapted to the planning speed according to the gear separation speed;

step S140, for each track point on the original planned track, replacing the planned speed with the adapted gear speed, to obtain a discretized planned track.

In practical application, many unmanned towers are based on the motion of the control tower crane of the operation gear. Taking three shafts of lifting, turning and luffing as examples, in the process of the movement of the tower crane, the lifting, turning and luffing are respectively provided with an operation gear or a control gear for controlling the running speed of the corresponding mechanism. For example, a handle-type operating lever of a tower cab or the like may be used to control the tower movement. Wherein there may be 3 to 5 gears per gear. For example, when the operation gear of the lifting shaft is shifted to the X gear, the lifting mechanism is lifted or lowered at a speed corresponding to the X gear; when the control gear of the revolving shaft is hung to the Y gear, the revolving mechanism revolves and operates at a speed corresponding to the Y gear.

For the control mode based on the running gear, a gear discretization method aiming at a kinematic trajectory is needed, so that the trajectory can meet the kinematic characteristic and the speed output can be discretized into the gear speed. In the control manner based on the operating gear, the gear speed is a discrete value corresponding to each operating gear. The controller generates an original planning track of the tower crane lifting hook and determines the planning speed of each track point. However, the planned speed of each trace point does not match the gear speed of each operating gear. Therefore, the planned speed of each current track point needs to be allocated to the gear speed one by one.

The embodiment of the application provides a track discretization method of an unmanned tower crane for adapting gear control, which aims at each track point on an original planning track, finds out a gear speed adapted to the track point to replace the original planning speed, and discretizes the original planning track. Through discretization processing, the control output is matched with the control mode, so that the control precision of the unmanned tower crane is improved.

In step S110, a gear separation speed between two adjacent operating gears is determined according to the gear speed of each operating gear of the tower crane. If the planning speed of a certain track point is smaller than or equal to the gear separation speed, assigning a relatively lower gear speed to the track point to obtain a discretized planning track; if the planning speed of a certain track point is greater than the gear separation speed, the relatively higher gear speed is assigned to the track point, and the discretized planning track is obtained.

In one example, the tower crane lifting shaft has a total of 3 operating gears. Wherein, the gear speed of 1 gear is 0.5 m/s, the gear speed of 2 gear is 1 m/s, and the gear speed of 3 gear is 1.5 m/s. A speed value may be taken in the range of 0.5 m/s to 1 m/s, determined as a gear split speed between 1 and 2. For example, a gear separation speed of between 1 and 2 is taken at 0.75 m/s. If the planning speed of a certain track point is less than or equal to 0.75 m/s, assigning the gear speed of 1 gear to the track point by 0.5 m/s to obtain the discretized planning track. That is, the shift speed adapted to the planned speed of the locus point is the shift speed of 1 st gear 0.5 m/s. If the planning speed of a certain track point is greater than 0.75 m/s, assigning the gear speed of 2 gears to the track point by 1 m/s to obtain a discretized planning track. That is, the gear speed adapted to the planned speed of the locus point is 1 m/s of the gear speed of 2 nd gear.

Similarly, a speed value may be taken over a range of values from 1 m/s to 1.5 m/s, determined as a gear split speed between 2 and 3. For example, a gear separation speed of between 2 and 3 is taken at 1.25 m/s. If the planning speed of a certain track point is less than or equal to 1.25 m/s, assigning the gear speed of 2 gears to the track point by 1 m/s to obtain a discretized planning track; if the planning speed of a certain track point is greater than 1.25 m/s, the gear speed of 3 gears is assigned to be 1.5 m/s, and the planning track after discretization processing of the track point is adopted.

In step S120, the acquisition controller generates a planned speed for each track point on the original planned track of the tower crane hook. In step S130, a gear speed adapted to the planned speed of each locus point is obtained according to the gear separation speed determined in step S110. If the planned speed of a certain track point is between two adjacent gear speeds, the planned speed is compared with the gear separation speed between the two adjacent gear speeds. If the planning speed is smaller than or equal to the gear separation speed, the gear speed matched with the planning speed of the track point is a relatively lower gear speed; if the planned speed is greater than the gear separation speed, the gear speed adapted to the planned speed of the locus point is a relatively higher gear speed. For example, if the planned speed of a certain track point is 0.8 m/s and the speed value is between 1 st and 2 nd and is greater than the gear separation speed between 1 st and 2 nd by 0.75 m/s, the gear speed adapted to the planned speed of the track point is 1 m/s of the gear speed of 2 nd.

In step S140, for each track point on the original planned track, the adapted gear speed obtained in step S130 is used to replace the planned speed in the original planned track, so as to obtain the planned track after discretization.

The above example is a track discretization processing example of a tower crane lifting shaft. The track discretization processing can be carried out on each shaft of the tower crane in the same mode, so that the control output is matched with the control mode, and the control precision of the unmanned tower crane is improved.

In summary, the embodiment of the application provides a tower crane track discretization method adapting to gear control, so that the tower crane track can meet the kinematic characteristic and discretize the speed output into the gear speed, the control precision of the tower crane is improved through track discretization, and the safety risk is effectively reduced.

In one embodiment, the method further comprises:

measuring the gear speed of the highest gear in the running gears;

Discretizing the original planned trajectory requires setting the gear speed of each running gear of each shaft. In one example, the gear speed of each shaft is set by first measuring the actual speed of the manual highest gear of each shaft, and the measured actual speed of the highest gear is the highest gear speed. And determining the gear speeds of other gears according to the actual speed of the highest gear and the actual Hertz value corresponding to other gears. Wherein the hertz value is indicative of the speed of the frequency converter. Each gear on the specification of the frequency converter is marked with a hertz value. The actual speed corresponding to the maximum gear Hertz value is measured, and the actual speed corresponding to other gear Hertz values is calculated by using a proportional relation formula, so that the gear speeds of other gears are obtained. The method for obtaining the gear speed of each gear may specifically comprise the steps of:

1) Five gears are shared by the tower crane lifting shafts (Lift). And (5) adjusting the speed gear to the highest gear 5 to control the tower crane to run. The actual measurement is made when the maximum speed is reached during operation. And collecting data to a file in the measuring process, and selecting the data of the highest-speed stable interval in the operation process of the tower crane for calculation. Typically, the tower crane is operated at a maximum speed and at a substantially constant speed for more than 3 seconds, during which time the speed is not changed much, and may only slightly shake, so that it may be considered that its operation is in a steady interval. The actual speed in the stable section is averaged, and the average value is taken as the maximum speed maxvel_lift (m/s) of Lift. For example, 100 sampling points are sampled within 3 seconds, and the average value of 100 sampling points is taken as the maximum speed. The maximum speed may be the highest gear speed. Maximum speeds maxvel_turn (radian/second) and maxvel_swing are found in the same way for both the Turn axis and the Swing axis at the highest gear movement.

2) According to the highest actual speed of each shaft and the corresponding Hertz value of the frequency converter, the gear speed of each gear of each shaft is calculated, and the conversion formula is as follows:

wherein Max _Hz The hertz value representing the highest grade; max (Max) _vel Gear speed representing the highest gear; G1G 1 _Hz Indicating the Hertz value of 1 grade; G1G 1 _Vel The gear speed of 1 st gear is indicated. By using the formula, the gear speed of other gears can be obtained by conversion according to the measured highest gear speed and the linear proportional relation between the Hertz value and the measured speed.

In one embodiment, the determining the gear separation speed between the adjacent operation gears according to the gear speed of each operation gear of the tower crane includes:

The gear separation speed of each shaft can be calculated on the basis of the calculated gear speed of the respective operating gear of each shaft. For example, the shift shaft has 5 shift positions, and the shift speed is 5, which are indicated by Th1 to Th5, respectively. And under the condition that the planning speed of the track points on the original planning track exceeds Th1 and is smaller than Th2, replacing the planning speed with the gear speed G1vel of the 1 st gear, and discretizing the track.

Each operating gear of each shaft has a corresponding gear speed and a corresponding hertz value of the frequency converter. Similarly to the manner in which the gear separation speeds are provided between the respective gear speeds, the hertz value of each gear may be provided between the hertz values of the respective gears. The Hertz number separation between speed 0 and speed 1 is expressed as Th1 Hz. The Th1Hz value may be set in a reasonable range in advance, for example, the range may be 0.20Hz to 0.30Hz. In one example, th1Hz defaults to 0.25Hz. Th2Hz is (G1 Hz+G2 Hz)/2, namely the average value of the Hertz values of the two gears is taken. The Hertz number separation value and the gear separation speed between other gears can also be calculated by adopting an average value. Referring to fig. 3, the data calculation results of the gear speeds and gear separation speeds of the respective gears of the three shafts of luffing, lifting and turning are shown.

In one embodiment, the obtaining the gear speed adapted to the planned speed according to the gear separation speed includes:

The gear separation speed is used as a separation value for assigning different gear speeds, and speed intervals corresponding to the running gears can be respectively defined based on the gear separation speed. For example, the tower crane lifting shaft has 3 operating gears. Wherein, the gear speed of 1 gear is 0.5 m/s, the gear speed of 2 gear is 1 m/s, and the gear speed of 3 gear is 1.5 m/s; the gear separation speed between 1 st gear and 2 nd gear is 0.75 m/s, and the gear separation speed between 2 nd gear and 3 rd gear is 1.25 m/s. The interval between the two shift speeds adjacent thereto for the 2 nd shift range is 0.75 m/s to 1.25 m/s, the above interval being the speed interval corresponding to the 2 nd shift range. In one example, the planning speed of a certain track point in the original planning track is 1.2 m/s, and the planning speed is within a speed interval corresponding to 2 nd gear, and the gear speed of 2 nd gear is 1 m/s and is taken as the gear speed matched with the planning speed of 1.2 m/s. And assigning 1 m/s to the track point, namely replacing the original planning speed by the adaptive gear speed of 1 m/s by 1.2 m/s to obtain the discretized planning track.

In one embodiment, the method further comprises:

In another example, the direction of the velocity of the tower hook movement may change during the operation of the tower. The kinematic velocity direction is symbolized. For example, if the upward direction is positive, the speed is 4m/s ² Indicating that the object moves upwards at a speed of 4m/s ² The method comprises the steps of carrying out a first treatment on the surface of the At a speed of-5 m/s ² Indicating that the object is moving downwards at a speed of 5m/s ² . That is, the absolute value indicates the magnitude of the velocity and the symbol indicates the direction of the velocity. It can be seen that the symbols herein have a different meaning than the mathematical signs. Mathematically, positive numbers are larger than negative numbers, which may represent a magnitude relationship in value. In the kinematics, the sign of the velocity is not related to the magnitude of the velocity, but the magnitude of the velocity is represented by an absolute value. Therefore, only the absolute value of the velocity can be processed during the track discretization process. For the case of reciprocating motion, the segmentation process may be performed for each segment of motion in a different direction. Extracting the absolute value of the speed for each section of motion respectively, and discretizing the absolute value; and meanwhile, the sign information of the speed is saved. After the speed value of each segment of motion is converted into the corresponding gear speed, the sign information of the speed is added to each segment track. And finally, integrating the segmented tracks to form a total running track.

For example, one direction may be set to be the positive direction of motion. The sign of the track speed is used to represent the positive or negative of the continuous speed in the planned track. Assuming that the upward direction is set to be the positive direction in the lift axis, the track speed sign is positive if the speed direction is upward, and the track speed sign is negative if the speed direction is downward. When track discretization processing is carried out, track speed symbols can be extracted first. For example, a planned trajectory has 1000 trajectory points, and the trajectory speed symbol may be stored in an array of 1000 elements. And then discretizing the planning speed of the track points in each section of planning track as a positive value. If the direction of the planned track is negative, the negative values are directly converted into positive values, and discretization is carried out by using the positive values. If the direction of the planned trajectory is positive, discretization is also performed with positive values. If the direction of the planned trajectory is positive or negative, the processing is performed for different direction segments. Each segment of the track in the negative direction and the positive direction independently executes one-pass discretization processing flow. For example, in a continuous planned trajectory, the first trajectory is positive, the middle trajectory is negative, and the last trajectory becomes positive again. At this time, the discretization process flow needs to be executed for the three tracks respectively, and the process flow is executed for three times. Track speed symbols of track points of the three tracks are respectively stored in 3 arrays. After the segmentation processing, namely after the continuous planning speed is converted into the corresponding gear speed, the information of the movement direction is added into each segmented track, and the segmented tracks are combined into a total movement track.

Fig. 4 is a schematic flow chart of a discrete algorithm of an embodiment of a method for discretizing a track of a tower crane according to an embodiment of the present application. As shown in fig. 4, when track discretization is performed, a track speed symbol temporary storage array is first reserved, and the speeds of track points are all absolute values. And then carrying out iterative processing on each segmented track. The gear separation speed can be changed appropriately during each iterative optimization. The gear separation speed may be adjusted linearly up or down, for example, by increasing both TH1 and TH2 by 1%, adapting the gear speed to the original planned speed. And (3) adjusting the gear separation speed TH each time of iteration until the error precision requirement is met. In one example, an upper limit on the number of iterations may be set, e.g. limiting the number of iterations to no more than 20000. If the iteration exceeds 20000 times and the matching is not successful, the precision requirement is not met, the program is jumped out and an error is returned. Referring to fig. 4, if the iteration number is not overrun, according to the gear separation speed TH, the gear speed is assigned to the track point of the speed interval corresponding to the planned speed value in the present gear.

The final objective of the track discretization process is to guarantee positional accuracy. Therefore, the path difference between the track after discretization and the track before discretization is small enough to meet the precision requirement. In one embodiment, the method further comprises:

Referring to fig. 4, integral calculation is performed on the gear speed adapted to each track point on the discretized planned track, so as to obtain a second path; integrating calculation is carried out on the planning speed of each track point on the original planning track, so that a first path can be obtained; and making a difference between the first distance and the second distance to obtain a distance difference L. If the distance difference L is smaller than a preset threshold value, the discretization processing result meets the error requirement. In this case, the discretized velocity is integrated to determine the position of each track point after discretization, and then the end point correction is performed on the track after discretization. For example, the displacement of the trajectory before the discretization is 100 meters, and the displacement after the discretization is 99.8 meters. The position of the last track point is corrected when the end point correction is performed so that the distance between the last track point and the start point is forced to become 100 meters. Through the end point correction, the tower crane can finally accurately reach a preset end point to achieve a preset operation target.

In one embodiment, the method further comprises:

Referring to fig. 4, after the discretization process, the velocity of the discrete track point and the velocity of the non-discrete track point are integrated to calculate the distance, and the distance difference L is obtained. And when the distance difference L does not meet the precision requirement, judging whether the distance difference L diverges. If the value of the path difference L is larger and larger, namely the position of the track point after discretization exceeds the position originally planned, the path difference L is determined to diverge. In this case, the shift-down process is started for the adapted gear speed of each locus point. Specifically, the shift-down process may be sequentially performed on the adapted gear speed of the specified locus point in a predetermined order.

Specifically, the downshift adjustment may be started from the highest gear in the order of the gear positions from high to low. For example, if the highest shift speed of the upshift is 3, the downshift adjustment may be performed for 3 first, and the locus point at which the shift speed is 3 is shifted down to 2. If all the track points with the gear speed of 3 are reduced to 2 gears, the path difference L still cannot meet the error requirement, and then the gear-down adjustment is performed for 2 gears. And adjusting the gear steps in sequence from high to low until the range difference L meets the error requirement.

In addition, during the downshift adjustment for the highest gear, the downshift process is performed one by one from both ends of the sequence number section of the highest gear trace point to the middle. For example, the track point a at the end point at one side of the sequence number section is first lowered to 2-level, and then it is determined whether the next path difference L meets the error requirement. If the distance difference L does not meet the error requirement, the track point B where the end point at the other side of the sequence number interval is located is reduced to 2 steps, and then whether the distance difference L meets the error requirement is judged. If the requirements are still not met, the track points adjacent to the track points A and the track points adjacent to the track points B are continuously reduced to 2 steps in sequence until the accuracy requirements are met, and finally the discrete values of each track point are matched.

For example, there are 5000 total track points in the planned track that need discretization. Each track point on the track is marked with a sequence number, and the sequence number information of the track point is stored in an array. In the downshift process, it is necessary to search all the discretized trace points and start the downshift adjustment from the highest gear. In one example, the highest gear of the upshift is 3, then the trace point for the 3 gear speed for the adapted gear speed needs to be retrieved in the above array. The sequence numbers of the track points are in a section, the sequence number of the track point at the left side in the section is minimum, and the sequence number of the track point at the right side in the section is maximum. It is assumed that the 3 rd speed corresponds to the interval between the 800 th track point and the 900 th track point of the entire track. The minimum number of the section is 800, and the maximum number is 900. The track points are downshifted one by one from the two ends of the interval to the middle. Specifically, the 800 th track point can be first reduced to 2 nd gear, and then it is determined whether the next path difference L meets the error requirement. If the requirement is not met, the 900 th track point is reduced to 2 steps, and then whether the next path difference L meets the error requirement is judged. If the requirements are not met, the 801 st track point and the 899 th track point are sequentially reduced to 2 grades until the accuracy requirements are met, and finally the discrete value of each track point is matched. The processing mode of downshifting from the two ends of the interval to the middle one by one is beneficial to continuous and stable operation of the tower crane speed, and good movement characteristics can be maintained in the whole control process.

In one embodiment, the method further comprises:

Referring to fig. 4, when the range difference L does not meet the accuracy requirement, it is determined whether the range difference L diverges. If the value of the path difference L is smaller, it is determined that the path difference L does not diverge. In this case, the shift speed TH is convergence-shifted according to the range difference L so that the range difference L continues to shift in the direction of decreasing, thereby ensuring that the end point of the track has no deviation. Specifically, the split point speed TH of each gear is adjusted once, and linear adjustment can be performed. If the error in the path difference L is large, then TH may be raised a little bit. For example, if each TH rises by one thousandth, the path difference L is shortened. If the difference of the first path before the discretization minus the second path after the discretization is greater than 0, in which case the discretized position does not reach the desired position, the value of TH is increased. And if the difference between the first path before discretization and the second path after discretization is less than or equal to 0, adjusting the value of TH to be smaller. Whether the value of TH is increased or decreased, the adjustment is aimed at making the absolute value of the path difference gradually smaller. If the absolute value of the range difference tends to be larger, the range difference diverges, and the processing is continued according to the diverged processing flow in fig. 4, namely, the shift-down processing is sequentially performed on the adapted gear speed of the designated track point according to the predetermined order.

In sum, when the range difference L does not meet the precision requirement, corresponding processing is performed on the two conditions of divergence and non-divergence of the range difference respectively until the error meets the precision requirement, and finally, each track point in the original planning track is matched with the adaptive gear speed, so that the control output is adaptive to the control mode based on the gear, the control precision of the unmanned tower crane is improved, and the safety risk is effectively reduced.

As shown in fig. 5, the application further provides a corresponding embodiment of the tower crane track discretizing device. Regarding the beneficial effects of the device or the technical problems to be solved, reference may be made to the description in the method corresponding to each device, or reference may be made to the description in the summary of the application, which is not repeated here.

In an embodiment of the tower crane trajectory discretizing device, the device comprises:

a first processing unit 100 for: determining gear separation speed between adjacent operation gears according to gear speed of each operation gear of the tower crane;

an acquisition unit 200 for: acquiring the planning speed of each track point on the original planning track;

the second processing unit 300 is configured to: obtaining a gear speed adapted to the planning speed according to the gear separation speed;

A discrete processing unit 400 for: and replacing the planning speed with the adapted gear speed for each track point on the original planning track to obtain a discretized planning track.

As shown in fig. 6, in one embodiment, the apparatus further comprises a third processing unit 500, the third processing unit 500 being configured to:

measuring the gear speed of the highest gear in the running gears;

In one embodiment, the first processing unit 100 is configured to:

In one embodiment, the second processing unit 300 is configured to:

In one embodiment, the second processing unit 300 is further configured to: dividing the original planned trajectory into a plurality of segmented trajectories based on different speed directions; for each track point on the segmented track, extracting the absolute value of the planning speed of the track point, and storing the speed direction information of the track point; obtaining a gear speed adapted to the absolute value of the planning speed according to the gear separation speed;

the discrete processing unit 400 is further configured to: for each track point on the segmented track, replacing the absolute value of the planning speed with the adapted gear speed to obtain a discretized segmented track; adding the information of the speed direction to the respective segmented trajectories; and synthesizing the segmented tracks to obtain a discretized planned track.

In one embodiment, the discrete processing unit 400 is further configured to:

Fig. 7 is a schematic diagram of a computing device 900 provided by an embodiment of the application. The computing device 900 includes: processor 910, memory 920, and communication interface 930.

It should be appreciated that the communication interface 930 in the computing device 900 shown in fig. 7 may be used to communicate with other devices.

Wherein the processor 910 may be coupled to a memory 920. The memory 920 may be used to store the program codes and data. Accordingly, the memory 920 may be a storage unit internal to the processor 910, an external storage unit independent of the processor 910, or a component including a storage unit internal to the processor 910 and an external storage unit independent of the processor 910.

Optionally, computing device 900 may also include a bus. The memory 920 and the communication interface 930 may be connected to the processor 910 through a bus. The bus may be a peripheral component interconnect standard (Peripheral Component Interconnect, PCI) bus or an extended industry standard architecture (Extended Industry Standard Architecture, EISA) bus, or the like. The buses may be classified as address buses, data buses, control buses, etc.

It should be appreciated that in embodiments of the present application, the processor 910 may employ a central processing unit (central processing unit, CPU). The processor may also be other general purpose processors, digital signal processors (digital signal processor, DSP), application specific integrated circuits (Application specific integrated circuit, ASIC), off-the-shelf programmable gate arrays (field programmable gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. Or the processor 910 may employ one or more integrated circuits for executing associated programs to perform techniques provided by embodiments of the present application.

The memory 920 may include read only memory and random access memory and provide instructions and data to the processor 910. A portion of the processor 910 may also include nonvolatile random access memory. For example, the processor 910 may also store information of the device type.

When the computing device 900 is running, the processor 910 executes computer-executable instructions in the memory 920 to perform the operational steps of the methods described above.

It should be understood that the computing device 900 according to the embodiments of the present application may correspond to a respective subject performing the methods according to the embodiments of the present application, and that the above and other operations and/or functions of the respective modules in the computing device 900 are respectively for implementing the respective flows of the methods according to the embodiments, and are not described herein for brevity.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Embodiments of the present application also provide a computer readable storage medium having stored thereon a computer program which, when executed by a processor, is configured to perform a method of discretizing a tower crane trajectory, the method comprising at least one of the aspects described in the embodiments above.

The computer storage media of embodiments of the application may take the form of any combination of one or more computer-readable media. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

The computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, either in baseband or as part of a carrier wave. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations of the present application may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, smalltalk, C ++ and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (for example, through the Internet using an Internet service provider).

Note that the above is only a preferred embodiment of the present application and the technical principle applied. It will be understood by those skilled in the art that the present application is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the application. Therefore, while the application has been described in connection with the above embodiments, the application is not limited to the above embodiments, but may include many other equivalent embodiments without departing from the spirit of the application, which fall within the scope of the application.

Claims

1. A method for discretizing a tower crane trajectory, comprising:

2. The method according to claim 1, wherein the method further comprises:

measuring the gear speed of the highest gear in the running gears;

3. The method of claim 1, wherein determining a gear separation speed between adjacent operating gears based on the gear speed of each operating gear of the tower crane comprises:

4. The method according to claim 1, wherein said deriving a gear speed adapted to said planned speed from said gear separation speed comprises:

5. The method according to claim 4, wherein the method further comprises:

6. The method according to any one of claims 1 to 5, further comprising:

7. The method of claim 6, wherein the method further comprises:

8. The method of claim 6, wherein the method further comprises:

9. A tower crane trajectory discretization device, comprising:

10. A computing device, comprising:

a communication interface;

at least one processor coupled to the communication interface; and

at least one memory coupled to the processor and storing program instructions that, when executed by the at least one processor, cause the at least one processor to perform the method of any of claims 1-8.

11. A computer readable storage medium having stored thereon program instructions, which when executed by a computer cause the computer to perform the method of any of claims 1-8.